Considering, for example, the traffic information application of the invention, there is growing frustration and much wasted time experienced particularly by mobile individuals in metropolitan areas, caused by encountering ever-increasing traffic congestion, unexpected traffic problems and frequent unpredictable delays. While radio stations provide a measure of periodic traffic updates, this requires constant listening to the particular radio station awaiting the time slot of traffic condition commentary, trying to sift from the omnibus traffic information supplied over relatively wide geographical areas the immediately useful information on the particular sector where the listener is located and is headed, and often receiving outdated and incomplete information, at that. At best, moreover, such traffic information is offered every fifteen minutes or so during rush hours and every half hour sandwiched with the news during off-peak times, and only for about 20-second time slots at that. Few cities provide any weekend coverage. The radio reports are delivered in rapid-fire form, embracing wide areas and are hard to understand, let alone visualize. In addition, due to limited air time, the traffic reporters rarely get back to tell the listeners that a problem has cleared up, thus precipitating unnecessary detours when not actually needed.
Underlying the present invention, as applied to this problem, is a novel technique, system and protocol that insures the continual collection of updated traffic information from a plurality of independent sources at a central station, the prompt telephone access to that station by the subscriber at any desired time, the specific limitation of the information supplied to the subscriber-selected geographical zone(s) of interest only, and the automatic update of the subscriber from the station if there are significant changes in the information within a predetermined time period following the last information transmission. The invention thus provides accurate, timely and complete information in a format that is easily discernable by the subscriber and does so in a way that minimally intrudes on the subscriber during his or her travels, with the goal of promptly giving the driver the information that is necessary to take an alternative route or make alternative plans. The user can literally plan the route to work, for example, while having morning coffee; or, while enroute, if the traffic conditions change, being notified immediately instead of having to wait for the next traffic report on the radio and/or possibly missing the opportunity to exit the route and avoid a problem. In addition, in accordance with the flexibility afforded by the invention, the driver has the freedom to listen to the radio station of his or her choice, or not to listen; or to listen to tapes instead of the radio; or to converse with a passenger or on the car phone -- all the while being assured that the subscriber will be afforded immediate knowledge of a traffic problem ahead.